I need to know where is the brake light switch is located,on a 2002 malibu

Look behind the pedal on the arm. If you jump with a jumper/or paper clip, brake lights should go on, if they don't a fuse may be bad.
You should have 12 volts at brake switch, and 12 going out when pressed, you can tell if brake lights are working by the ability to place into gear(not 100%)

There is a free repair available for this problem as detailed here: http://ww2.justanswer.com/uploads/Bluegorilla/2009-04-22_031710_hazard_flasher_policy.pdf

You'll need to contact your local GM dealer to verify coverage by that policy extension mentioned in the prior post. Your vehicle may be out by mileage if over 150,000 miles.
Even still, the Hazard switch replacement may not correct a "no brake lights" concern. (We don't know yet why raymondgardner needs the location for that switch)
Diagnosis is required as this is a complex circuit.

What are your symptoms?